At Wednesdays debate in Arizona, there was no mention of the environment or climate at all.

Its not an especially hot topic for Democrats, either. President Barack Obama mentioned climate change only once in his recent State of the Union address, lamenting that progress was stymied by partisan gridlock.

Bipartisan progress on the environment used to be common. Republican President Richard Nixon and a Democratcontrolled Congress worked together to create the Environmental Protection Agency and pass the Clean Air and Clean Water Acts, saving millions of American lives. A similar alliance during the Reagan administration ratified the Montreal Protocol to phase out ozonedestroying chemicals, which were also potent greenhouse gas is michael kors factory es. Bushs administration, making the United States the first industrialized nation to ratify a climate change treaty.

Some Republican candidates have taken strong environmental positions in the past. As governor of Massachusetts, Mitt Romney promised to place public health above dirty power plants and supported and signed capandtrade legislation to reduce carbon dioxide emissions. As recently as June he told New Hampshire voters, I believe the world is getting warmer, and I believe that humans have contributed to that.

Not so many years ago, Newt Gingrich cosponsored a bill in the House of Representatives stating that climate change was resulting from human activities. In his famous sofa ad with Nancy Pelosi, he said, our country must take action to address climate change. As recently as 2007, he opined in his book Contract with the Earth that the high priority of the e is michael kors factory nvironment must be affirmed.

With the primary season heating up, however, the green in Republican seems to have faded to brown. In October, Romney said, we dont know whats causing climate change on this planet. Gingrich, who now wants to replace the EPA, stated recently, I actually dont know whether global warming is occurring. And some tea partyers around the country are fighting local initiatives to combat climate change through increased energy efficiency and reduced traffic congestion.

Have views evolved because climate change science has become less certain? Not at all. As two scientists who study the earth for a living, wed point to one fact among many for anyone unsure about the reality of climate change: The North Pole is melting before our eyes. Summer ice is only half the size it used to be just a few decades ago and is much thinner, down to a few feet thick in many places. All this in less than a human lifetime.

If the scientific evidence is strong, there must be another reason why candidates no longer acknowledge climate change. Could it be the loss of a political center and increasing stridency on both sides of the aisle? Such a change is unfortunate because climate change needs careful consideration, without partisan politics.

People who see the evidence for climate change as compelling can use it as motivation to reduce carbon emissions and promote efficiency and green technologies. People more skeptical of the evidence can be motivated by national security, balance of trade and global competition to save energy and reduce oil imports. George W. Bush said as much in 2008: America has to change its habits. It has to get off oil. And given nonpartisan data showing that coal pollution kills tens of thousands of people each year is michael kors factory , everyone can support phasing out the oldest, most polluting coal plants. is michael kors factory